


Infernal Influence

by moricad



Series: Cross Your Heart [5]
Category: A3! (Video Game)
Genre: Addiction, Anal Sex, Angst, Blow Jobs, Demon Sex, Eating Disorder Not Otherwise Specified, Established Relationship, Extremely Dubious Consent, M/M, Mental Instability, Suicidal Thoughts, Supernatural Elements
Language: English
Status: Completed
Published: 2021-02-25
Updated: 2021-02-25
Packaged: 2021-03-16 07:08:50
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,132
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29696892
Author URL: https://archiveofourown.org/users/moricad/pseuds/moricad
Summary: It had been one year since the pact.The consequences of having a relationship with a demon were now a part of every day life as they adjust to Kazunari's frail human state beginning to decline. Kazunari can't help but wonder how much longer he can hold on; Itaru can't help but begin to lose hope.Can a solution be found in time or is it already too late?
Relationships: Miyoshi Kazunari/Chigasaki Itaru
Series: Cross Your Heart [5]
Series URL: https://archiveofourown.org/series/2175609
Comments: 12
Kudos: 13





	Infernal Influence

**Author's Note:**

> _It just was meant to be a Halloween sex one-shot..._
> 
> Thanks for sticking around! This is part 5/6 in Cross Your Heart. It's best read in context with the other chapters. More than usual... I wouldn't recommend it without the context.
> 
> Mind your tags, please. The summary alone will give you enough vague context to jump into part 6 if you need to skip this part.

It had been one year since the pact.

Kazunari’s body shuddered violently as he came, Itaru’s mouth firmy sucking him dry. Moaning on Itaru’s couch and slowly regaining his composure, the demon below looked up with scared, concerned eyes.

“Kazunari, can you hear me?” Itaru quickly scrambled up onto the couch; horns and tail retreated as lingerie was magically replaced by an oversized t-shirt and shorts.

“Itarun… yeah, I’m here.” Kazunari rubbed the sweat from his forehead and allowed Itaru to fall into his arms.  _ How long… _ Kazunari instinctively reached for a nearby blue journal, Itaru always had it nearby for him after they had sex.

Itaru gave Kazunari a gentle kiss and backed off, laying his head on the blonde’s frail lap, large eyes trained on his expressions all the while. Kazunari reached for a pen behind his ear and was confused to find none. Itaru shyly handed it up to him, and he smiled down kindly as he took it.

“What’s today, Itarun?”

“April 15th, Senpai is out drinking for his birthday,” Itaru obediently answered.

Kazunari frowned in contemplation as he flipped through his journal. “That means… yours is soon, right Itarun?” 

Itaru smiled sadly from below, “I suppose it is.”

Kazunari turned to his last coherent entry and smiled, eyes running over formalities and mathematics. “You let me drink last time?”

Itaru laughed from his lap, “You kept complaining you didn’t have the INT to run the numbers otherwise.”

Last time Itaru fed off of him… it was the 8th. “It’s just been a week, Itarun,” Kazunari sighed, they had to stick to their schedule. Itaru agreed to stretch himself further, right? It should be every week and a half now.

“Sorry, but you made me promise that you’d be okay for Tsuzuru’s birthday party. You wouldn’t shut up about it two times ago.” Itaru pouted, a slight anger flushing his annoyed cheeks at Kazunari’s accusations. “This is me correcting the schedule.”

Kazunari flipped back to check. 

_ SPECIAL NOTE!! Future me~ Itarun has our permission to change it up! Tsuzuru’s birthday will be totes lit! It’d... be unnatural if we weren’t there after all. _

_ Aah… I’m totes a dummy sometimes… _ Kazunari ruffled Itaru’s mop of hair as an apology and went to look over his math from last week.

An important fact automatically was missing. “How… how much lucid time do I have right now?”

Itaru frowned. “You probably only have two or three good days before the withdrawal starts to stack. Lately you can make it... until the fifth day before you completely break.”

That’s five or six days… of being in  _ that _ state… every feeding cycle.

“I’m… so sorry…” Itaru choked out from below. Kazunari gently caressed Itaru’s face with his palm.

“It’s not your fault,” he whispered, truthfully. This was all his own fault. 

The demonic pact between them kept Kazunari well for a while. Much longer than Itaru anticipated. Most humans in long-term sexual partnerships with an incubus or succubus die from withdrawal or hysteria just five or six months into it, if they were extraordinarily lucky at that. For him to only be this far gone since their pact was made was nothing short of a miracle.

He flipped forward a page to see complicated math formulas. “I need a drink…” Kazunari muttered under his breath as he tried to parse the information.

“Denied. I want to spend time with you sober. You don’t give me any attention when you drink.” Itaru’s serious, steady eyes never left his face.

“Alright… I’ll figure it out babe.” Kazunari got to work, and before long figured that it was a chart keeping track of his regression, and formulas to predict the path of the deterioration to come.

“You wouldn’t tell me before... how does it look?” Itaru’s eyes opened curiously.

“I…” Kazunari hesitated. He didn’t want to tell Itaru the news now either. He wasn’t reaching the brink for a while, but his mental deterioration was steadily increasing. “I’m not going to be able to do our new summer play this year…” He was already missing out on so much of their early rehearsals. All he really wanted was two things: to stand proudly on stage with his friends and to enjoy his relationship with the love of his life. Why was that so much to ask for?

“I’m… so sorry…” Itaru’s voice quivered. Kazunari shushed him and went back to petting his hair as his other hand shakily crimped the edge of his notebook. Tears couldn’t be held back as they dropped and splattered on the page below. Behind the notebook Itaru’s own tears silently rolled down the side of his face.

“I’ll… have to leave Mankai soon. There’s really no avoiding it unless…” Kazunari stopped as his voice quavered.  _ Unless I just end this all myself _ , he found himself thinking automatically. Losing memories and parts of himself hurt; losing out on what he loved most in life hurt. But Kazunari couldn’t do that. He dragged Itaru into this relationship, and he would take responsibility for it as much as he could in his life.

“A… after Kniroun is done we’ll leave together,” Itaru whispered, the heartbreak palpable on his lips.

“No, you stay. You belong here.” Kazunari quickly scowled and shot Itaru an annoyed look.

“I belong to you. With you,” Itaru retorted, pulling the neck of his baggy shirt downwards. The bold outline of a circle holding a hibiscus flower peeking into view. The symbol of his promise to protect Kazunari for as long as he should live.

“I thought it was the other way around,” Kazunari whispered, the distant memory of their vows still planted firmly in his mind.

“Don’t be an idiot, Kazunari.” Itaru sighed as he wiped away what remained of his tears. “I’ll start looking for apartments near my work for us, alright?”

“Mhm. Maybe… I can hurry my graduation too. See how my credits come together,” Kazunari mumbled as he turned to the next blank page in his notebook. “Let’s go to Veludo Arts tomorrow after you get off work.” 

He hastily began to scrawl a list with shaky handwriting:  _ Things to do ASAP.  _ As dumb as worrying about his degree sounded in these circumstances, it was something he could leave behind for his family… so he should try, right? Proof that even in this shattering, breaking existence he could accomplish one of his dreams. That it wasn’t all for nothing.

Kazunari sighed. This was just too much. What was somebody supposed to do in his circumstances though? Sit around and do nothing? He motioned for a second book on the table, and Itaru passed the soft pink leather-bound pages over. This one always made him feel better. Reviewing unnecessary, he flipped to the next open page immediately and took a deep breath.

Soon, his newest proof of love complete, he set both of his notebooks aside. He waited for Itaru to slowly crawl into his lap and straddle him, a ritual his mind desperately clings to. With a smile Itaru did just that, throwing his arms languidly around his shoulders and off the back of the couch. Unlike his movements, his face was attentive, high strung pink eyes darting quickly to take in as much of Kazunari’s face as they could.

“Is there something wrong with my face…?” Kazunari smiled shyly, his body already creaking and aching from supporting Itaru’s weight.

“No… it’s perfect.” A melancholy smile met Itaru’s lips. Kazunari found himself wrapping an arm around Itaru’s waist and pulling him close. Desperately, his quivering lips reached out towards Itaru’s firm, pink ones. His other hand found soft blonde highlights that tickled against his skin.

As stupid as it seemed… looking into Itaru’s gentle eyes... these soft tender moments seemed so worth it. Despite it all.

Finally, Itaru leaned in to meet Kazunari’s scared lips with his own. Kazunari felt a dampness running down his cheeks as they kissed. Both their arms moved to desperately hold the other close. But Kazunari couldn’t tell… were those flowing wet tears Itaru’s or were they his own?  
  


Itaru checked his watch as he stepped into the shop. A quick stop at the convenience store for some cola, it wouldn’t keep him for too long. At the counter there was a bright display full of bright packaged candy. Sour peach rings, delicately wrapped lollipops, and a variety of flavored chocolates begged for attention. Itaru felt a pang in his chest, reaching out instinctively to grab a few different sweets. Kazunari loved candy… but Itaru doubted that he would eat any of it.

A short walk to their apartment. It was only a few minutes from the store and Itaru’s work. Really, the perfect location for the two of them to live together. Itaru just wished these past few months together on their own could have been happier.

An autumn chill met him outside. Wind kicked up his hair as he began the short walk home. Wait, that wasn’t the wind. A soft, broken voice took root in the back of his head, “ _ Itarun… Itarun… where are you…? Itarun… _ ”

It was to be expected. Kazunari needed him today. He needed him every three days now. Itaru ducked into an alley way as he felt a sharp tug at the small of his back. Then, he was in a dark room, their bedroom, standing before Kazunari.

“Itarun…?” The quiet voice mumbled in disbelief. 

Kazunari was completely naked on the bed, eyes wide and gaunt, hair disheveled, and rubbing Itaru’s pink wedding garter to his face- the important item that allowed him to summon Itaru to him. Itaru frowned and turned around, the drawers of their dresser were turned out, clothing scattered everywhere. He hadn’t hid it well enough.

“Let me put these bags away. I’ll be right back, Kazunari.” Itaru turned to leave before he could see or hear anymore, shutting the door behind him.

His composure needed to be kept. Kazunari needed him, after all. He couldn’t crumple here in the hallway. He couldn’t pause to think. Mechanically, cola went into the fridge, candy went onto the counter for now. Maybe he would eat some later. A faint hope that he didn’t expect to be answered.

The cushions from the couch in the living room were upturned, scattered to the corners of the room. Where did he find the strength to do that? Even that should be too much for him right now. No, don’t think about it.

Itaru set his shoes by the front door and hung up his coat. Kazunari’s own outerwear untouched for weeks, silently gathering dust. They haven’t been outside together since… No, don’t think about it.

The door to the spare room was open, so he closed it. Kazunari’s art supplies were in there and he didn’t want to see the state of the room. He’s been too scared to go in there... No, don’t think about it. Kazunari needed him now.

Itaru steeled himself. He wasn’t hungry but they were in the late game now. Everything was for Kazunari. For those precious few moments they could maybe... hopefully have together afterwards. He announced himself at the door as he turned the handle.

Kazunari was kneeling over on the bed now, hands desperately dug into his hair, his dark coffee-stained roots beginning to show. The pink garter belt was still in his hands as he cried into the mattress. 

This wasn’t his Kazunari, not anymore. He was gaunt from not eating every day, his cheery demeanor was gone. No more intelligent conversations. No more dates. No more sharing precious moments together with the human he had learned to love. No, don’t think about it.

“Hey Kazunari. I’m here. Sorry I kept you waiting.” Kazunari seemed to snap out of his trance at Itaru’s voice, looking up from the bed with dull, mossy eyes. Itaru slowly approached the bed, sitting down on the edge as he looked at what remained of his beloved.

“Itarun…?” Kazunari achingly came over to Itaru’s side. “Itarun…” Tears filled his eyes, turning them into muddled, murky swamps. Itaru was quick to try and wipe them away.

“Right, I’m here.” Itaru reached over and planted a kiss on Kazunari’s forehead. 

“It hurts… I tried… I can’t… help,” Kazunari’s thoughts spilled out quicker than he could talk. Or maybe he just didn’t know the right words anymore. No, don’t think about it.

Kazunari latched a hand into Itaru’s hair, planting his dry lips on Itaru’s. The gentle rasping of skin on skin as his other hand desperately tried to get himself going. Trying to find some kind of relief that he couldn’t reach on his own anymore.

Itaru opened his mouth and was met with Kazunari’s rough tongue hysterically exploring his mouth, no reason or thought behind his erratic movements. Itaru calmly tried to meet it with his own, but nothing stopped Kazunari’s unstable actions. The dry rasping of skin sped up, but Itaru knew that nothing would come of it. 

_ May as well get this over with, _ Itaru pushed Kazunari off him and back onto the bed. The blonde let out a groan as he hit the sheets. Was he too rough? Did that hurt him? Itaru threw off his shirt and laid next to him, brushing messy blonde bangs away from his partner’s forehead.

Kazunari didn’t react to the gentle touches, instead he rolled on top of Itaru and began to lick and suck at Itaru’s soft pink skin. Hurriedly, he began to take off Itaru’s pants as Itaru gently lifted his hips to allow access. Itaru popped open a lube bottle and sat up briefly to slick Kazunari up, then gently began to stretch his own entrance while the impatient, whining blonde had to be held back at arm’s length.

Satisfied enough, Itaru fell back into the pillows and Kazunari quickly scrambled between his legs. Itaru flinched as Kazunari entered him, turning his face to the side to avoid the eyes devoid of the life and happiness that he had so fallen in love with. No, don’t think about it. Not now.

Itaru bit his lip and held back tears as Kazunari weakly lifted his legs and continued to thrust into him. It didn’t take long for him to set a ruthless pace. The power of addiction was real and Itaru hated himself for turning into the drug that caused all this pain. No, don’t think about that either. Please, don’t cry in front of him.

Suddenly, it was wet. The gentle spattering of tears on his chest, but they weren’t his own. He looked up, against all of his instincts and saw bright green eyes, burning with frustration and desire, gently raining. “Itarun… I’m so sorry…” The Kazunari above him was… this didn’t make sense…

“K-kazunari?” Itaru choked out between dry sobs. “Is that really you?”

“I hate that you’ve been doing this for me… I totes hate it so much!” Familiar words and familiar movements as Kazunari’s eyes shut and he clamped down on his bottom lip. 

Why was this happening? What’s going on? Itaru hasn’t seen him in… at least a week… probably longer. Time was never his strong point when he wasn't immersed in a ranking event. It’s been too long, that’s all he knew.

Carefully, he reached up to Kazunari’s face, fearing the illusion was fake. Fearing that a single touch would dissolve and ruin everything. Yet, he couldn’t stop himself as his hand gently cupped the side of his face. Kazunari smiled, a melancholy smile full of missed opportunities and longing. 

His hips became erratic, still moving on autopilot as his body chased the high it needed to escape its pain. To escape its reality. Tears rolled gently from Itaru’s eyes as Kazunari trembled and spasmed above him, finally filling Itaru with his warmth.

He collapsed immediately, Itaru ready to catch him and pull him close.

“H...how long was I away…?” A nervous question asked between panting breaths.

“... a while.” Itaru choked out between dry sobs. 

“Last time… how long was I here for…?”

“... not long enough. Let’s take care of you while we can.”

Itaru drew Kazunari a warm bath and got some rice and vegetables cooking in the kitchen. Every opportunity he got, he ran to the bathroom and was met with a frail smile and wave.  _ He’s… still here…. _

Itaru watched in fascination as Kazunari sat at the table and ate. It’s been so long. Kazunari’s regular clothes now hung on him, too big for his delicate frame.

“Itarun… before I go…” Kazunari began speaking between bites.

_ No, please don’t go… _ Itaru nervously ran his fingers through his hair. No, don’t think about it. Listen to him.

“There are two things.” Kazunari met Itaru’s nervous eyes, the shine of intellect and love already beginning to fade. “First, go to the art room. I feel like… it’s important.”

Itaru didn’t want to go in there. It’s where the mindless shell of his lover spent his time when he was at work. He was scared of what he would find.

“Second, the pink leather book…” Kazunari shook as he pushed it towards Itaru across the table. Itaru remembers seeing Kazunari always writing or drawing in this in the early stages of his deterioration.

“If I don’t come back…”

_ No, don’t give it words! Don’t give it power! _ Itaru felt frustrated tears forming in his eyes.

“... I made this for you. Please, always keep it with you.”

Itaru nodded, despite his grit teeth. “On one condition,” he whispered as he took the book. 

Kazunari smiled lazily, fighting against sleep. “Yeah…?”

“Promise me you’ll come back one more time.” 

“Hmm… I hope I will.” Kazunari’s exhaustion and frail state had caught up with him finally as he gently laid his head down on the table. “I’m… tired… can you help me once more…?”

Itaru picked up the blonde, nuzzling into his hair as he carried him bridal style to the bed. “Please, Kazunari, promise me,” he desperately whispered.

“I promise I’ll try. I totes love you. I promise... And I’m… I’m so sorry.” A yawn escaped his lips as he drifted off in Itaru’s arms. Itaru carefully tucked him into bed and set to cleaning up the apartment.

Many restless hours later, Itaru finally found himself in front of Kazunari’s studio - the spare bedroom. His cold, clammy hand gently turned the knob, and he carefully entered the room. Itaru froze at the sight. It wasn’t the messily scattered notebooks and papers haphazardly thrown about. It wasn’t the paint splatters on the carpet and walls. It wasn’t even the holes in the wall and faint specks of blood that surprised him.

Against the back wall was a sizable painted canvas. Two lone figures stood at the edge of a cliff, their backs to the viewer. The one with a blue jacket waving his hat as he took in the view, the other with faint horns laughing as he tried to pull the other away with their linked hands. Below the cliff was a painting of Veludo Way, the Mankai Dormitory and Theater both in view thanks to the skewed perspective. The city seemed to grow more foreign and bizarre as it stretched towards the horizon. Then instead of a sky, a huge traditional Japanese style wave threatened to engulf and destroy it all. 

Was the tiny Kazunari on the cliff waving to welcome it, or was it to show he wasn’t scared and would stand strong despite the impending tide?

Has he been trapped in...  _ there _ all this time, desperate to break out and reclaim his own consciousness? Should he have come in here sooner? Would it have helped him at all?

Itaru couldn’t help but think about it. He collapsed to the floor and let out a long, drawn out, entirely inhuman wail that was full of all of the pain and hurt of human emotions. 

As tears, snot, and screams wracked through his body, he desperately wanted to do something. Anything that could help. He needed to give it all that he could, to make up for abandoning him. To make up for believing that hope was lost and it was only a matter of time until the end. Sleeping could wait, gaming could wait, working could wait.

He needed to figure something out fast, for the next time his love came back to visit him. He promised, after all.

But the crying… the crying wouldn’t wait.  
  


_ Itarun… Itarun… Itarun…  _

The pain. The pain wouldn’t stop. The burning in his chest, in his joints, in his loins. The stinging sensation in his eyes. The dry cracking inside his nose. The pins and needles living in his fingers.

Kazunari shivered painfully.  _ Itarun… where… _

There was something important. It would bring Itarun to him. But… where was it? Kazunari stood up off the bed, his stomach churning painfully as he collapsed to the floor.

Didn’t Itarun know how much he was hurting? Did he care? Was… there a reason to care?

Kazunari’s eyes wanted to flicker to life, but the fuse box inside was broken.

A sound at the door. Hurried footsteps. Strong hands on his body.

_ Itarun…! _ Kazunari’s senses heightened. His groin began to stir. The relief for his pain so close. Right here.

“Hey, careful! Please, don’t hurt yourself.” Itarun set him back on the bed. 

Words… what do they mean… Kazunari tried to catch his breath.

“I’ll take care of you today too. Please don’t worry about me.”

_ Care… _ Kazunari knew that one. Clumsily he tried to undo his pants button, but his hands were awkward and ineffective.

“Shhh, shhh…” A hand stroking his head… Kazunari felt himself relax, although he didn’t understand why.

Something in his chest hurt, but whenever he scratched at it he felt nothing. 

Kazunari felt his pants come off and a strong hand hold down his waist. It was enough to pin him in place. There just wasn’t enough energy to move. 

“Itarun… care… please,” Kazunari’s only words spilled from his cracked lips.

Itarun smiled at him kindly. He said to remember the promise, but what did that mean? He swept Kazunari’s hair off his forehead and planted a kiss on his cheek before moving downwards.

Kazunari suddenly began to feel good. Itaru’s mouth was moving around him and Kazunari couldn’t help but try to thrust his hips further in. The aching in his bones began to subside. The popping and creaking of his joints was now forgotten. Breathing through his nose was getting easier.

“Itarun…” Kazunari moaned the name of his savior desperately. Itarun’s head began to move faster and faster. It felt so good. It felt too good.

Something began to stir within Kazunari, a door being knocked on in the back of his mind.

No, Itarun was already here. That was the only door knock that mattered.

Itarun reached up and grabbed Kazunari’s trembling, scared hand, lacing their fingers gently together.

What was this? Kazunari tried to shake his hand away, but Itarun just grabbed on tighter as he sloppily sucked his cock.

Kazunari was scared, he trembled and began to cry. Why were things so weird this time? Itarun’s other hand gently massaged his thigh. Why was he so kind?

Why was he taking such good care of him? Why… why…

Water burst through the door in his mind and spilled out through his eyes with heart wrenching sobs. “Itarun…! Why do you still do this for me?!” Kazunari screamed out.

Itarun… no, Itaru… clenched Kazunari’s hand even tighter, took his cock even deeper. Kazunari cried as he came, his spare hand grasping at beautifully highlighted hair that was the color of soft wheat. 

Kazunari didn’t have time to sink into the mattress before Itaru was on top of him, kissing him passionately. Kazunari smiled as the tears ran down his cheeks. Too soon, Itaru pulled away.

“We need to make this quick. Please, take this and read.” Serious pink eyes met his now sparkling peridots. Kazunari didn’t need to ask what was going on. It was obviously apparent… it’s been a while. His mind was still annoyingly foggy despite his relief. He shakily opened the paper presented to him and tried to parse the words. What was Itaru up to...?

“Just do your best. I love you so much, Kazunari.” Itaru gently kissed away his tears and held his spare hand in his own.

Through the painfully receding pins and needles… what else did Itaru have in his hand?

Kazunari felt the fog coming back in.  _ So soon…? _ If this was going to be his last visit… the least he could do was this. Whatever it was. Anything to make Itaru happy.

Slowly, he began to read words in a language not his own.


End file.
